Vivek Goyal wrote: > o Currently a request queue has got fixed number of request descriptors for > sync and async requests. Once the request descriptors are consumed, new > processes are put to sleep and they effectively become serialized. Because > sync and async queues are separate, async requests don't impact sync ones > but if one is looking for fairness between async requests, that is not > achievable if request queue descriptors become bottleneck. > > o Make request descriptor's per io group so that if there is lots of IO > going on in one cgroup, it does not impact the IO of other group. > > o This patch implements the per cgroup request descriptors. request pool per > queue is still common but every group will have its own wait list and its > own count of request descriptors allocated to that group for sync and async > queues. So effectively request_list becomes per io group property and not a > global request queue feature. > > o Currently one can define q->nr_requests to limit request descriptors > allocated for the queue. Now there is another tunable q->nr_group_requests > which controls the requests descriptr limit per group. q->nr_requests > supercedes q->nr_group_requests to make sure if there are lots of groups > present, we don't end up allocating too many request descriptors on the > queue. > > Signed-off-by: Nauman Rafique <[email protected]> > Signed-off-by: Vivek Goyal <[email protected]>
Acked-by: Rik van Riel <[email protected]> _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
